Study of Kinematically Determinedτ′Decays

Abstract

We have studied a sample of 144 ${\tau }^{\prime }$ decays in which, for the first time, all the kinematical quantities are determined. The dependence of the matrix element on the neutralpion energy has been measured and a linear extrapolation has been made to zero four-momentum. The result is consistent with the soft-pion prediction of current algebra.